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https://srf.ch

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
80
GRADE
B
FIX
1
REVIEW
2
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 2 REVIEW 1 FIX
D
Green Hosting
Action
Unknown
FIX
Unknown
Info::
Hosting provider could not be identified
Without knowing the provider, we cannot determine their energy sourcing. Check with your hosting provider about their renewable energy commitments.
Info::
Green hosting status based on known provider commitments
Green hosting detection uses a curated database of provider renewable energy commitments. This is not a real-time verification. For authoritative checks, visit thegreenwebfoundation.org.
Green HostingUnable to Determine
Hosting Not identified✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

B
Transfer Efficiency
84% efficient
REVIEW
84% efficient
Info::
Transfer efficiency: 84%
An estimated 187 KB (16%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 187 KB of unused JavaScript. This wasted data produces 0.05g of unnecessary CO2 per page view.
84% efficient

Total waste: 187 KB (16% of page weight)

Unused JS 187 KB

0.05g unnecessary CO2 per visit

Actual transfer 1151 KB
Theoretical minimum 964 KB
Potential savings 187 KB (0.05g CO2)

See Deep Analysis sections above for specific optimizations.

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A
CO2 Per Page Load
0.32g CO2 per view
PASS
0.32g CO2 per view
Info::
0.32g CO2 per page view
This page transfers 1.1 MB, producing an estimated 0.32g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.06g, network 0.06g, end-user device 0.20g.
Got: 0.32g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 38.2 kg CO2/year
With 10,000 page views per month, this page would generate approximately 38.2 kg of CO2 annually — equivalent to charging 4778 smartphones.

0.32g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 79% of websites

Sustainable Web Design model v4 · Page size: 1.1 MB

Your site
0.32g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.06g
Network
0.06g
End-user device
0.20g
At 10,000 monthly views: Monthly: 3.2 kg · Annual: 38.2 kg · ≈ 4778 smartphone charges
A+
Repeat Visit Weight
97% cached
PASS
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 33 KB (vs 1151 KB first visit). 99 of 100 resources are served from browser cache, saving 0.31g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.32g)
First visit
1151 KB
Repeat visit
33 KB

97% reduction on repeat visits

Saving 0.31g CO2 per returning visitor

99 resources served from cache · 1 resources re-downloaded

A
Carbon Budget
21th percentile
PASS
21th percentile
Info::
0.32g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 79% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 21th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.32g

21st percentile

Cleaner than 79% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 47% cleaner ✓
vs Target 36% cleaner ✓
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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